[PATCH v3 4/4] arm64: mte: Optimize mte_assign_mem_tag_range()

@@ -49,7 +49,31 @@ long get_mte_ctrl(struct task_struct *task);
 int mte_ptrace_copy_tags(struct task_struct *child, long request,
 			 unsigned long addr, unsigned long data);
 
-void mte_assign_mem_tag_range(void *addr, size_t size);
+static inline void mte_assign_mem_tag_range(void *addr, size_t size)
+{
+	u64 _addr = (u64)addr;
+	u64 _end = _addr + size;
+
+	/*
+	 * This function must be invoked from an MTE enabled context.
+	 *
+	 * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and
+	 * size must be non-zero and MTE_GRANULE_SIZE aligned.
+	 */
+	do {
+		/*
+		 * 'asm volatile' is required to prevent the compiler to move
+		 * the statement outside of the loop.
+		 */
+		asm volatile(__MTE_PREAMBLE "stg %0, [%0]"
+			     :
+			     : "r" (_addr)
+			     : "memory");
+
+		_addr += MTE_GRANULE_SIZE;
+	} while (_addr < _end);
+}
+
 
 #else /* CONFIG_ARM64_MTE */
 

@@ -150,18 +150,3 @@ SYM_FUNC_START(mte_restore_page_tags)
 	ret
 SYM_FUNC_END(mte_restore_page_tags)
 
-/*
- * Assign allocation tags for a region of memory based on the pointer tag
- *   x0 - source pointer
- *   x1 - size
- *
- * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and
- * size must be non-zero and MTE_GRANULE_SIZE aligned.
- */
-SYM_FUNC_START(mte_assign_mem_tag_range)
-1:	stg	x0, [x0]
-	add	x0, x0, #MTE_GRANULE_SIZE
-	subs	x1, x1, #MTE_GRANULE_SIZE
-	b.gt	1b
-	ret
-SYM_FUNC_END(mte_assign_mem_tag_range)